Looks like the DNS record was updated today, and the following nameservers are setup:
NS.ROBINSON-DEFEHR.COM
and NS2.ROBINSON-DEFEHR.COM
ROBINSON-DEFEHR.COM does not exist, so this could be PART of the problem, it could also be a typo and NS.ROBINSON-DEFEHR.COM maybe should read:
NS1.ROBINSON-DEFEHR.COM
I think the NS prefix indicates that he is using 2 servers at Network Solutions..........